For our art project for Alchemy this year, we plan to build a huge archway in the forest with a portal to hyperspace. This is no easy task, so we decided to do some small-scale prototyping so that we can look into some of the challenges of this build and play with different effects to see what looks the coolest.

Our design is based around an infinity mirror, which is a cool device that is build from one regular mirror and one two-way mirror. Lights placed in the center echo between the two mirrors until they fade too low to be seen. The viewer looks through the transparent side of the two-way mirror and can see the effect move with their perspective.

Kevin and Edward working with the assembled frame.
That's the two-way mirror in the foreground.

I had some help with the build from Kevin and Edward, who came in for the Tuesday night open house and got recruited to the project. Nathan (not pictured) also joined in to help, so we had 4 people working on it.

We also made the two-way mirror using a standard piece of glass from Home Depot and some mirrored window tint that we ordered online. That was fairly easy to do with 4 people on it, but it would be a total nightmare to do by yourself. Important lesson from the prototype: tint is REALLY difficult to get right.

Once we had both mirrors, we did a quick test by holding the two-way mirror over the regular mirror with the LEDs laid out in between to see how far apart we'd like to space the two.

Because it didn't need to be pretty, but it needed to be easy to disassemble and reassemble, we opted to just build it out of 2x4s and support the frame with cross-braces from the back.

We slotted the 2x4s on the table saw so that we could slide the glass in and out of the assembly. Then, after more tries than I care to remember, we got the frame cut down to a size so that the slots matched the 24x30 dimensions of the glass pieces. We slid the mirrors in while we only had 3 of the 4 frame pieces assembled so that we could get a tight fit with the supporting cross-pieces on the back.

We left the fourth side wall off until the end so that we could attach it with a hinge and a lock, which allows us to pull it apart as needed. We attached a hinge and a locking mechanism that we had laying around the space and the frame was done.

Rather than painting it, we opted to just use black tape to darken the inner walls. Next, we measured the total width of the inner chamber, which was 4x the width of the LEDs as we had planned. For the tunnel to look "even", the spacing between the two LED strips had to be double the spacing between each strip and the side wall. We did the math and found two jigs that were those heights and used them to lay out the strips. Interestingly enough, the adhesive on the backs of the LED strips can't handle the heat that the strips put it out... so we ended up stapling them to the walls.

We accidentally switched Nathan for bizzaro Nathan in the process.
The real Nathan is trapped in mirrorworld somewhere. Safety third!

Finally, we attached the control box and IR receiver for the strips to the top of the hinged piece. The primary colors worked fine, but when trying to get the ting to fade, it started flashing purple and got unresponsive to the IR remote. The problem ended up being that I was using a 12v 1a power supply and needed at least 3 amps. A bigger power supply fixed the issue.

After about 3 hours of work, we got a working prototype finished and learned A LOT about building the full-scale model. Some of these issues would have cost hundreds of dollars or pushed us behind schedule waiting for stuff in the mail. The total cost of this prototype was $100 and I'm gonna turn it into a coffee table when I'm done.

Here's a video walkthrough of the final prototype (before I fixed the amperage glitch).